1. Field of the Invention
This invention relates to an improved tamper evident end cap assembly for a drug loaded syringe to seal it and to cap it protectively prior to injecting a patient with the drug; and also, to the end cap assembly and a package, as a combination, wherein the end cap assembly is encapsulated within the package to maintain it in a sterile condition prior to capping a drug loaded syringe with it; and further, it relates to a drug loaded syringe capped with the tamper evident end cap assembly ready to be opened to inject a patient with the drug or to return the drug load, if not used by the patient, to be down loaded at a station and recycled. The invention also relates to a process of manufacturing the end cap assembly and of using it by installing it on a mating syringe.
2. Description of the Related Art
This invention is disclosed in three forms:
a first form, which is a combination, composed of a drug loaded syringe having a nozzle with a discharge port or luer opening and a tamper evident end cap assembly according to the invention installed on the nozzle sealing and closing the luer opening and which cannot be removed to gain access to the drug load without creating palpable evidence of tampering;
a second form, which is another combination composed of a) at least one tamper evident end cap assembly which has a structure according to the invention, and b) a sterile shipping and storage package encapsulating it, the end cap assembly including its end cap assembly luer lock syringe cap captivated within the end cap assembly is adapted to be removed from the package and installed on the nozzle of a mated standard syringe in a position from which it cannot be removed without creating evidence of the removal, and
a third form which is an improved combination, composed of a) a tamper evident end cap assembly which includes b) a luer lock syringe cap coaxially captivated yet rotatable on its axis within the assembly, the assembly being for mounting of it over the discharge port or luer opening of a dose loaded standard and mated syringe, the end cap assembly being improved with respect to known devices by structure set forth fully in this disclosure which, among other elements, includes a) a first one way drive means component on the syringe cap, b) a floor portion in the assembly to maintain the cap within the assembly which floor portion also has an axial one way drive means component, which mates with the first component to comprise a one way drive means to move the syringe cap axially in one direction only to tighten it on a syringe nozzle, and is disengaged and inefficient upon rotation in the other direction of rotation and c) a centering means on the floor portion to guide the syringe cap of the end cap assembly into coaxial engaged relation with other end cap assembly parts.
The invention is also of a process of manufacture of the foregoing structure and of the use of it.
Throughout this specification, the phrase “standard syringe” is used. This phrase is intended to refer to a plurality of “carbon copy” syringes, usually made by a single manufacturer. A “carbon copy” syringe is one of a group of syringes of the same type, as regards size, shape and configuration which are intended to be used at a particular medical facility or location. By way of explanation, as is well known in the field, many facilities use standard syringes made and sold by a particular manufacturer, such as those of the Becton Dickenson Company. However, there are syringes of many other manufacturers which are also in use at many facilities and these are also referred to herein as standard syringes. The point is that the subject invention is sized and shaped to mate with all of the “carbon copies” of a standard luer lock type syringe stocked for use at a given facility, regardless of the manufacture of the standard syringes used at that particular facility.
As further background generally, and as indicated in FIG. 1, a standard luer lock type syringe 11 is usually of plastic material; and it typically includes a barrel 1 with a nozzle 2, which are usually transparent or translucent, and define an elongate interior chamber which is in fluid communication with an axial luer, passageway or long channel 3 in the syringe nozzle 2 and that terminates distally at an opening or discharge port 4; and b) an axially slidable piston 5 in the barrel with a head 6 provided with a circumferential gasket means 7. When assembled, the end face 9 of the head 6 of the piston confronts channel 3 and closes the opening or discharge port 4 of the syringe. The piston also includes a push rod 8 extending proximally from the head 6 and from barrel 1 for axially manipulating the head end face 9, and consequently, the axial location of the piston head 6 in the barrel 1, either closer to or withdrawn from, the luer opening or discharge port 4. In use, the standard syringe 11, after being loaded with a drug at the pharmacy, is sealed by closing the discharge port 4 with a mating member often referred to as a luer lock or syringe cap 14 as shown in FIG. 2. To do this the cap 14 may be provided with threads 3″ to be threadably connected to the nozzle by a suitable mating connection means 3′. As shown in FIGS. 1 and 2, the threads 3″ are located on the interior of the nozzle 2 so as to connect to an exterior of connection means 3′. The connection means of the luer lock or syringe cap 14 may, alternatively, be of the type which includes the male radially extending flange portion also indicated as 3′ in FIG. 2. The connection may also be of the type which includes a set of circumferentially spaced ears (not shown) on the outer surface of the luer lock cap provided to threadably engage the threads on the syringe. As shown, generally, in FIG. 2 in either case, the ear type or the flange type, the radially extending portion 3′ of the cap 14 is sized and configured for threaded receipt in the annular, correspondingly threaded recess 3″ of the nozzle 2. In another form, the connection means may be merely reversed and comprise a female connection means portion on the luer lock or syringe cap for threaded connection with a male connection means portion on the nozzle 2. In some structures, the nozzle portion 2 and syringe cap 14 may each have a correspondingly tapered mating configuration for press fitting them together to join them. In this specification the term, “connection means” refers to and embraces the structure shown and or described as well as other known and usually routine means of installing a syringe cap 14 and a mated syringe 11 to close the discharge or dispensing port 4 of the syringe 11.
Turning now to the background purposes of the invention, in a hospital, for example, it is common for medical doctors to order that a patient be given an oral or an injectable dose of a drug. In the case of an injectable drug, the dose is quite often filled by a pharmacist at a location which may be regarded as a syringe filling station. It is often far from the place where the patient is to be injected. It is quite often that a syringe filling station is located on one floor of a hospital and the nurse's station is located on another hospital floor. Indeed, at large medical facilities, a syringe filling station may resemble a factory on the hospital grounds from which drug loaded syringes are delivered to multiple nurse stations in multiple other hospital buildings. Because of the remote location of many nurse's stations relative to an associated syringe filling station, a loaded syringe is very often given to another person for delivery to a nurse's station for subsequent dosing of the patient by a duly qualified nurse or other medically trained person.
During the process of loading the syringe with a drug dose, the delivery of the dosed syringe and its handling in general prior to the step of actually dosing a patient by injection, there is a danger of contamination. This invention guards against that happening.
Also, especially in the case of a very expensive drug or an addictive dose, there is a danger of tampering with the loaded syringe in an effort to improperly gain premature access to the drug. A real danger is that such inappropriate action may result in a substitution of an unauthorized material in the syringe, simulating an actual prescribed or real dose. Obviously, a substitution of a substitute dose for a real dose, such as a substitution of a saline solution for a dose of morphine, may have extremely serious consequences. Thus, there is a problem of knowing if a sealed drug laden syringe has, or has not, been exposed to contamination or compromised by tampering. This and other problems have been further described in my earlier granted U.S. Pat. No. 4,667,837 and in other patents including in U.S. Pat. No. 5,328,474.
This invention addresses problems of making and using drug loaded syringes, some of which are described in each of the above noted patents. This is because problems remain in the field since the introduction of products according to those two patents. These include problems of easy and inexpensive assembly of the end cap assemblies in the manufacture of them, problems involved in the assembly of an end cap assembly on a drug loaded syringe at a drug filling station, and problems of maintaining sterility during storage at the manufacturing facility of the end cap assemblies, transport of them to a medical or other facility storage, and problems of storage of them at a medical facility. In summary, the invention addresses problems in handling the end cap assemblies as one is made and used at different stations by different persons. In general, this invention provides an improved tamper evident end cap assembly being less expensive, safe and structured for convenient manufacture and use.
Specifically, this invention addresses outstanding problems by providing: a) an improved tamper evident end cap assembly including a captivated luer lock syringe cap for closing the discharge port in the nozzle of a loaded syringe, b) an improved sterile package with the end cap assembly encapsulated within it, for transport to, and, prior to use, for storage at a medical facility; and c) an improved combination of a drug loaded syringe and tamper evident end cap assembly for use in dosing a patient. The end cap assembly is especially adapted to mate with and be used with what is referred to herein as a standard syringe, one which is a “carbon copy” of the type used at a given medical facility where it is drug loaded and delivered to a nurse's station for injecting a patient with the dose. Any unauthorized access to the loaded drug contents, once the syringe has been loaded and closed prior to its ultimate use, requires removal of the syringe cap by an unauthorized person. The fact that such a removal occurred is clearly evident, if it does in fact happen.